While most of Metro’s weekend disruptions are for maintenance on the rail system, the transit authority does sometimes adjust the train schedule for projects supervised by other transportation agencies.

This upcoming Red Line disruption is such a case. Metro crews will be performing track maintenance, but by stopping the trains between Fort Totten and New York Avenue, the transit authority also will be creating a safe work zone for the rehabilitation project above the tracks on the New York Avenue Bridge. Here’s the full schedule.

Red Line

From 10 p.m. Friday through the train system’s midnight closing Sunday, free shuttle buses will replace trains between Fort Totten and New York Avenue. Rhode Island Avenue and Brookland stations will be closed.

Trains will operate on the normal weekend schedule between Shady Grove and New York Avenue and between Glenmont and Fort Totten. Add about 30 minutes to normal travel times for getting through the work zone on the shuttle buses.

The last trains from Glenmont will depart 27 minutes earlier than usual, at 2:10 a.m. Saturday and Sunday, and at 11:10 p.m. Sunday.

If you’re traveling on the east side of the Red Line to downtown D.C. for an event like the 7 p.m. Saturday hockey game at Verizon Center, you can avoid the work zone by getting off at Fort Totten and taking a Green Line train to Gallery Place.

Blue Line

From 10 p.m. Friday through Sunday’s closing, trains will share a track between Stadium-Armory and Addison Road. Workers will be repairing the slabs beneath the rails.

Trains will leave the stations at the end of the line about every 20 minutes. Add about 20 minutes to get through the work zone.

Green/Yellow lines

From 10 p.m. Friday through the Sunday closing, Green Line trains will share a track between Fort Totten and Prince George’s Plaza. Crews will be working on the rails.

Yellow Line trains will operate between Huntington and Mount Vernon Square only, rather than continuing north to Fort Totten. Trains will operate every 16 to 20 minutes on each line. Allow about 20 extra minutes of travel time.

Robert Thomson is The Washington Post’s “Dr. Gridlock.” He answers travelers’ questions, listens to their complaints and shares their pain on the roads, trains and buses in the Washington region.